[fixed] Java OpenGL JOVR - head tilt causes lighting change

I'm still struggling to get my basic examples running, but it seems like I'm still tripping over some basic OpenGL stuff.

Currently with my LWJGL3 experiment I'm getting a change in lighting when I move my head around. The floor should be black and white tiles, but the whole surface fades between black and white.

https://github.com/WhiteHexagon/example-jovr-lwjgl3-rift

With my JOGL version, I have the tiled floor working, but the head movement feels wrong. I've tried taking it back to basics using glRotates (RiftClient0440NoMatirx.java) but it still feels wrong. I'm also wondering if this is something to do with scale. I using 1 OpenGL unit as 1 meter. So to draw the floor I translate up the y-axis 1.8 units = 1.8m. Is this a sensible approach? for seated experience should we half that or something?

https://github.com/WhiteHexagon/example-jovr-jogl-rift

I know that this should be working with more modern based OpenGL and shaders, but for my understanding I want to get these direct mode examples running before I take the next step. Sorry for asking again for help!

[EDIT:Seems to have been a problem with texture generation]